91 F150, 5.0, M5OD, 213402 miles on the odometer.

The test results / State Allowance (I'm guessing)
Idle Speed CO=4.42% / Greater Than 1.20%
High Speed CO=8.59% / Greater Than 1.20%
Idle Speed HC=399 / Greater Than 220 Parts Per Million
High Speed HC=352 / Greater Than 220 Parts Per Million

Before I had it tested here is what I did:
Replaced Plugs (Motorcraft copper core)
Replaced Plug wires (Ford Racing 9mm)
Replaced Cap and Rotor (Duralast from AutoZone)
Replaced Air Filter (Motorcraft) got rid of the K&N
Replaced Crankcase Breather filter
Replaced PCV
Original coil was tested (ohomed out) by Counter dude at AutoZone, thought they would use some type of special test equipment: Checked out within allowable parameters according to their store manual.

Thinking that next step would be to do the Seafoam procedure in the intake, Seafoam in the crankcase prior to a much needed oil change. Seafoam in the fuel tank. Check and reset base timing. Run EEC test procedure and see what it tells me. Anything else I should do?

BTW, a while back I replaced the leaking water pump and t-stat. Before that, I did the stupid thing of adding a bottle of coolant system leak stop, so needless to say the crap is still in the system, probably coating the Water Temp sensor too. I have a replacement sensor if needed.

Hope my attempt at listing the test results makes sense.

Thanks in advance,
Ed

 

the water temp sensor may not be reading hot enough to lean out the fuel. i would replace it.

 

I was thinking that too. Should be verified when I do the EEC self test right?

 

Maybe. It will only throw a code if it's below a certain threshold. I would flush the whole system out. Also replace the radiator cap. A leaking cap will cause emissions readings like yours - those are usually from either a cold engine or a bad vacuum leak. When it's warm what does it idle at?

 

Can't tell what the rpm is at idle since my goofy factory tach always reads about 3 grand. Once in a while it'll read properly, but the majority of the time it reads high. I'll have look for my clip-on tach and see what it says.

I'll replace the temp sensor, flush the system and replace the cap. Since it was leaking so much coolant before the pump change, I was only adding water to the radiator. So there is probably no anti freeze in it anymore, just water. I still have to top off the radiator every time I drive it; not a lot, but enough to be annoying. Water is going somewhere, just need to find out where.

As for the possibility of a vacuum leak, what would be a way to check it for it? I do have a vacuum gauge and a MityVac tester.

 

You could also clean the sensors and replace those that aren't working right.

 

Start by checking the vacuum at idle. If you have a bad leak it will be low. There are also a bunch of other things to look for with a vacuum gauge. Keep this page handy: How to Use and Interpret a Vacuum Gauge

 

Thanks for the replies so far, and for the link to interpreting vacuum gauge readings. I've seen something similar, if not that exact page, but didn't save the page. I'll be heading out once it cools down a bit and try the vacuum test. If I have time I may try to do the EEC Self Test.

 

Update; just did the vacuum test. With gauge plugged into the upper intake manifold using the line off the vacuum tree that goes to the AC vacuum system, the gauge reads about 18 inches of mercury and the needle stays steady (idle RPM). When the accelerator pedal is pressed all the way to the floor and released, the needle goes to zero and then back to 18; needle stays steady.

Same results when the brake booster line is used, but the reading was at 16 inches of mercury at idle rpm.

While the engine was running I sprayed TB cleaner anywhere I thought it could have a vacuum leak. No noticeable decrease/increase in idle speed. I did spray a little into the air intake tube just to see how the engine reacted; it nearly stalled the motor with just a few seconds worth of cleaner being sprayed. Hope it didn't do any damage to the brand new air filter I installed.

I'll try to run the EEC self test tomorrow and check the base timing. I have a Sun Pro tach/dwell meter that I can also hook up to check the rpm, just not sure which of two coil wires to hook it up to. Anyone reading this knows which one of two to use?

 

Another update:

Checked the base timing with the SPOUT plug/cap removed. Right at 10 degrees BTDC. Checked it when the engine was cold and when it got warmed up. Same reading. Reinstalled the SPOUT cap and it seemed to be reading about the same or a couple of degrees more. I need to see if this should be a concern or not.

Also hooked up the Sun Pro tach/dwell meter, and as far as I can tell, idle rpm is between 750 and 800. It was hard to tell the precise rpm since this tester is analog and can be used for 4, 6, and 8 cylinder engines.

No time to do the EEC self test tonight. Hopefully I can find a tester that will display the number codes on the screen as opposed to blinking lights. I know that I could just use the CEL, but it would be just my luck to decipher the blinking CEL incorrectly.

 

Valid concern. People do it all the time. I recommend the Innova Equus 3145. In addition to reading all the codes correctly, there is a great diagnostic section in the manual that will tell you how to run the timing advance test. From the sounds of it the computer isn't advancing the timing the way it should but I would buy the reader and check that out first. I think I paid less than $30 on ebay for my reader.

 

Update III

Sorry about this being a bit winded.

Well today I got around to flushing out the cooling system. It took a long time to get all the leak-stop crap out of it. Ran the engine a few times during the back flush. Didn't replace the ECT sensor because I didn't have the correct socket to get it off with. I didn't want to brake anything in the process. Even flushed out the coolant reservoir before adding anti-freeze.

Ran a bottle of Seafoam to the intake system, damn was there a lot of smoke. I was concerned that someone would call the fire department. It took a while for all the smoke to clear out of the exhaust.

After all that, since the engine was pretty warmed up, I decided to try the self test. The KOEO didn't show any faults. But the KOER returned trouble code 44, which it displayed twice. Did both test twice with the same results. According to the Ford Engine/Emissions Diagnosis manual, the code described it as the "Thermactor air system inoperative" (if I'm reading the manual correctly). According to the Ford Fuel Injection & Electronic Engine Control book (byCharles Probst), the code definition is "secondary air injector system inoperative (right side)".

Both manuals recommend doing a vacuum test on both the TAB/TAD solenoids. I had to remove both from the top of engine just to get at the vacuum ports. I connected the pump to the supply port and pumped it down to 15 inches, both solenoids did leak down ever so slightly. Not sure why the Probst book says to hook up a vacuum gauge to the output port, but I also tested it that way too. The gauge on the pump seemed to show more bleed down with the vacuum gauge installed, and also didn't show any vacuum from the output port. It's possible that the connection weren't leak-free, which may have caused the slight bleed-down.

I also vac tested the vacuum reservoir and it cheked good. But the black line that supplies vacuum to the TAB/TAD/EGR solenoids wasn't holding any vacuum at all. Tried to inspect the line, but it was hard to see the entire length since most of it is covered buy the plastic convoluted protector. I'm thinking about just replacing the tubing with some rubber vacuum hose, and mimicking the way Ford designed it. Hopefully it will fix the high HC and CO. And it surely doesn't take much to damage those brittle tubes; I had to splice in some rubber tubing on the red tube that supplies vac to the reservoir.

May have to replace the entire vacuum distribution tubes with something more durable. Any suggestions welcomed.

Thanks for reading and replying.

 

you could just get truck plates and call it a day....thats what I would do

 

If you're talking about licenses plates, I don't believe we have that option here in Nevada. But we can have the emissions test waived only after spending $450 on parts and labor, and cost for self-repairs are not considered towards the test waiver. How gracious of them huh?

 

Well I'm still trying to get the trouble code 44 fixed. I replaced the vacuum lines from the reservoir to the TAB/TAD solenoids as well as to the EGR solenoid, and also replaced the line to the EGR valve (it broke at the fitting). Ran the KOER test twice and still got code 44. I even ran it a third time after disconnecting the battery, and leaving it disconnected for about five minutes. Still had the same code. What I didn't do was run the engine long enough for the computer to relearn before doing the test again.

My next step is to replace the rest of the vacuum lines, but not sure which of the two (TAB/TAD) solenoids gets connected to which of the two valves that are behind the upper intake. Can anyone here help with this? If replacing the vacuum lines fail to remedy the problem, it looks like I'll need to proceed to testing the actual thermactor components. Has anyone ever done this?